Mary-Kate Olsen seeks treatment for eating disorder

(USA TODAY) -- After months of speculation about her emaciated appearance, Mary-Kate Olsen has entered treatment for an eating disorder, her publicist said Tuesday.

Mary-Kate, one-half of the famed Olsen twins, "made a very courageous, precautionary decision," said Michael Pagnotta, the twins' longtime publicist. " Mary-Kate is taking charge in making this decision. She wants to be healthy."

The brunette actress, who just turned 18, is undergoing treatment at an undisclosed location. Pagnotta could not say what type of eating disorder Mary-Kate has, but Us Weekly, which first reported the rehab news, says it's anorexia.

Anorexia is characterized by self-starvation and excessive weight loss.

Pagnotta "categorically denies" rumors that drugs are involved.

Twin sis Ashley is doing fine, Pagnotta says. "Ashley has complete faith in Mary-Kate and has been very supportive of her, as have her family and friends."

Fans and celeb magazines expressed shock and concern at Mary-Kate's appearance April 29 at the unveiling of the twins' star on the Hollywood Walk of Fame. The whispers grew louder at the May 4 New York premiere of their first big-screen film, New York Minute, which performed poorly at the box office.

During interviews to promote the film, both twins denied that Mary-Kate had an eating disorder and dismissed rumors of drug use.

The twins even joked about tabloid gossip when they hosted Saturday Night Live on May 15. In a skit where they pretended to be paparazzi, they called out to actors playing the twins: "Mary-Kate, you're so skinny! Eat a sandwich!" and "I hear they get paid in cocaine!"

There's "a lot of denial" in patients with eating disorders, says Susan Ice, medical director of the Renfrew Center in Philadelphia. "The biggest hurdle is acknowledging a problem."

Other stars, including Christina Ricci and Jamie-Lynn DiScala, have battled eating disorders.

"Western society has placed demands on women to stay thin," says Jeanne Rust, executive director of Mirasol, an eating disorder clinic in Tucson. The pressure is even more intense in Hollywood.

The Olsen twins have been in showbiz practically since birth, starring on the TV sitcom Full House when they were 9 months old. Since then, they've become superstars among the preteen set. They have their own line of straight-to-video films, books, dolls, video games, fragrances and a Wal-Mart clothing label.

On June 13, the fraternal twins celebrated their 18th birthday by taking control of their empire worth an estimated $300 million. The next day, Ashley was photographed vacationing in Mexico, without Mary-Kate.

Pagnotta says Mary-Kate and Ashley still plan to attend college together at New York University this fall.